Video Clocked output and VGA

Well,

I am tryng to use buffering for video streams in my system.

To buffer an 640*480 video frame, i need at least 1.2Mb of memory, so i have to use sdram.

This sdram is an SDR (the DE2 has only a 8M SDR sdram), and in a tutorial for the sdram they(Altera) say that sdram need a -3ns delay.

So, my system is this:http://img62.imageshack.us/img62/7727/videotest.png (http://img62.imageshack.us/i/videotest.png/)

But the output is still incorrect, and i don't know why.

and If I use buffer inside the deinterlacer, I have the same troubles...